1. Field of the Invention
This invention relates generally to exercise apparatus. More specifically this invention relates to exercise apparatus for simulating swimming.
2.Description of the Prior Art
The prior art discloses a variety of swimming apparatus. The prior art generally shows a bench or support for a person to lay in a principally horizontal position while the user moves their arms and legs in manner that to lesser or greater degrees simulate swimming. It is important that the bench have a fully cantilevered arrangement since the arms of the user may extend as much as 8 to 12 inches below the user's hips when executing a full swimming stroke. U.S. Pat. No. 4,844,450 discloses a swimming device that uses a cantilevered bench which improves arm motion and overrunning clutch assemblies to provide leg and arm resistance through a series of cables for the arms and levers for the legs. The overrunning clutch assembly uses a single flywheel with overrunning clutches to power the flywheel by the cables on the power stroke and springs to return the cables on the return stroke.
According to long standing principles of swimming a proper swimming stroke incorporates large amounts of torso rotation to cut water resistance and increase arm stroke efficiency. Corresponding head rotation accompanies the torso rotation. The use of large flat support benches as shown in U.S. Pat. No. 4,844,450 do not readily permit natural torso or head rotation.
U.S. Pat. No. 5,158,513 discloses a simulated swimming apparatus that again consists of an arrangement of overrunning clutches, pulleys, flywheels, recoil handles and springs for providing arm resistance. The apparatus of U.S. Pat. No. 5,158,513 uses a pivotable cantilever body support to facilitate rolling of the body and a radial pivoting chin support to allow side to side head movement. The rolling motion produced by the pivoting members aids in approximating the torso and head rotation of swimming motion but requires a complicated and often uncomfortable torso and head support.
When actually swimming the speed of the swimmer will also change the swimmers body displacement and attitude with respect to the water. As the swimmers speed increases more lift is experienced and the body rises out of the water. This decreased body displacement does not occur evenly. Since the hips represent a heavier part of the body, the swimmer's head and shoulders elevate with respect to the rest of the body. Most of the available swimming devices do not allow adjustment of the torso support in a manner that will simulate changes in swimming speed by adjusting torso attitude.
U.S. Pat. No. 4,830,363 discloses a device for simulating swimming that uses individual biased pulleys for the arm motion. U.S. Pat. No. 4,830,363 describes a bench having an adjustable center point but does not provide a cantilevered bench to avoid restriction of arm movements. The bench also adjusts in the middle which does not permit the body to slant downward from the head to the hips. A great deal of attention has been focused on arm and body motions, but the leg motion has received little attention. The kicking motion is important to achieve the full conditioning benefit of swimming. In actual swimming kicking provides only about 20% of the propulsion during a distance swim. However, kicking consumes a large portion of the available oxygen. Thus, while kicking may have lesser importance for propulsion, kicking is a vital part of swimming when it is used as an aerobic exercise. Since the legs comprise such large muscle groups, the limited motion that kicking demands actually creates a large a portion of the oxygen debt produced by the person performing the exercise and burns a lot of calories in the process. Although most of the swimming exercise machines make some provision for leg exercise, the movements poorly approximate actual leg movement during swimming. Previously discussed U.S. Pat. Nos. 4,844,450, 5,158,513 and 4,830,363 all restrain the legs to a rigid swinging motion about a horizontal axis. The axis of rotation in these devices is offset from the hip rotation point of the user. This offset, usually in excess of 2 inches creates and eccentric motion that causes the leg to slide on the support surface. In such an arrangement the foot will slide along the support approximately 21/2 inches for foot of vertical rise. Thus the bottom of the leg cannot be attached to the support for a secure feeling and the sliding motion of the leg creates discomfort for the user.
In addition to the fixed hinge support, the system of U.S. Pat. No. 4,830,363 (discussed above) uses pistons to resist leg movement. Piston like devices usually have a location that creates a leg resistance in a direction greatly different from that encountered during the natural kicking motion of swimming.
U.S. Pat. No. 3,731,921 uses fixed guides to provide resistance and support for a kicking motion. The guides again constrain the legs in a restricted fashion that is unlike the natural motion of kicking.
A swimming machine that offers a lesser degree of leg restraint while permitting some form of kicking motion is U.S. Pat. No. 4,948,119. This patent seats the user in an upright position. Pulleys mounted overhead give the user of this device a full range of arm motion. Lower pulleys having cable ends strapped to the legs pull outwardly on the legs. Although the legs have greater freedom for kicking, the force direction exerted on the legs by the pulley is much different than that encountered in normal swimming.
In addition to closely approximating swimming it is highly desirable for the apparatus to permit compact storage of the fully cantilevered bench arrangement. The typical frame structure of cantilevered swim exercise machines makes collapsing of the apparatus impractical.
Accordingly it is an object is to provide swimming simulation apparatus having a simplified bench that approximates the swimming motion of the torso and chin without obstructing arm movements.
Another object of this invention is to provide a swimming simulation apparatus that allows adjustment of the upper torso support in manner that resembles the changes in buoyancy that occur with actual swimming activity.
A further object of this invention it is to provide leg exercise in an exercise machine for simulating swimming that more closely approximates the actual leg movements associated with swimming than that offered by the prior art.
A yet further object of this invention is to provide a swimming simulation apparatus with a cantilevered bench that collapses to a compact form for storage.